win32 fix: disable alsa search because it isn't available on win32
win32 fix: disable alsa search because it isn't available on win32

svn path=/trunk/KDE/kdelibs/phonon/; revision=657100

sandsmark/phonon-visualization-gsoc,sandsmark/phonon-visualization-gsoc,sandsmark/phonon-visualization-gsoc,sandsmark/phonon-visualization-gsoc